80 BULLETll^ 15 7, U. S. NATIONAL MUSEUM 



Forms.' — The two forms of this butterfly found in the District 

 and vicinity are, when typically developed, widely different. 



In one (pi. 7, figs. 1, 2), the fore wings are about 30 mm. long 

 in the female and about 28 mm, long in the male. On the upper 

 surface the ground color is dark, and the brown of the fore wings 

 and of the outer half of the hind wings sometimes shows dark green 

 metallic reflections. On the underside the whole of the hind wings 

 and the apical portion of the fore wings is dull pinkish red, often 

 quite uniform, but usually darkest in a long irregular narrow tri- 

 angle bordered by irregularly crenulate lines running from a base 

 near the outer angle of the hind wings to an apex near the anal 

 angle. This triangle often contains two small oval blue spots nar- 

 rowly ringed with lighter, or some trace of such spots. 



This form has curiously soft wings and always feels as if it had 

 recently emerged from the chrysalis. Its wings are rarely broken 

 or torn, though they may be rubbed. It is sluggish, and rarely flies 

 for more than 50 feet or so, alighting usually on the ground. 



In the other form (pi. 7, figs. 3, 4), the fore wings measure about 

 27 mm. in the females and about 24 mm. in the males. The ground 

 color above is lighter brown. Beneath the ground color of the hind 

 wings and the apex of the fore wings is light gray, usually slightly 

 tinged with buff, and there are two conspicuous oval black spots 

 about as broad as, or narrower than, an interspace, which are nar- 

 rowly ringed with buff not far from the outer margin of the hind 

 wings. 



In this form the wings are dry and brittle, and nearly all the 

 individuals caught are nicked or more extensively damaged. This 

 form is exceedingly alert and active, a much stronger flier than 

 the other, and if alarmed flies rapidly away, usually not pausing 

 until it is out of sight. It is fond of flowers, and if it rests it always 

 chooses the summit of a tall weed or a tall dead stem or bare ground 

 from which it can easily dart in any direction., 



In 1926 I wrote that the form with the underside of the wings dull 

 pinkish red is the commonest about Washington in the fields where 

 the food plant {Agalinis purpurea) is abundant, while the small 

 light active form is found sparingly with the other. I remarked 

 that the small light form differs from the larger and darker one in 

 keeping mostly well above the ground, resting on the tops of the 

 higher plants and darting off at the slightest provocation, and that 

 it is much more frequently to be seen on barren hillsides, about the 

 city parks and streets, and generally in unfavorable localities. I 

 added that it is this form that occurs in New England. 



I suggested that the small light form is a special form particu- 

 larly fitted for long-continued flight and therefore especially adapted 

 for distributing the species. 



